Semiconductor device and method of fabricating the same

ABSTRACT

A semiconductor device includes a via structure and a conductive structure. The via structure has a surface with a planar portion and a protrusion portion. The conductive structure is formed over at least part of the planar portion and not over at least part of the protrusion portion of the via structure. For example, the conductive structure is formed only onto the planar portion and not onto any of the protrusion portion for forming high quality connection between the conductive structure and the via structure.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application is a continuation application of an earlierfiled copending patent application with Ser. No. 12/913,748 filed onOct. 27, 2010, for which priority is claimed. This earlier filedcopending patent application with Ser. No. 12/913,748 is in its entiretyincorporated herewith by reference.

The present application also claims priority under 35 USC §119 to KoreanPatent Application No. 10-2010-0061080, filed on Jun. 28, 2010, in theKorean Intellectual Property Office, the disclosure of which isincorporated herein in its entirety by reference. A certified copy ofKorean Patent Application No. 10-2010-0061080 is contained in the parentcopending patent application with Ser. No. 12/913,748.

TECHNICAL FIELD

The present invention relates generally to semiconductor devices, andmore particularly, to a semiconductor device and a method of fabricatingthe same to include a conductive structure formed onto a partial portionof a top surface of a via structure.

BACKGROUND OF THE INVENTION

Conductive lines and vias are commonly used as interconnect structuresto form an integrated circuit of a semiconductor device. Vias are usedto connect conductive lines formed on multiple levels of interconnectlayers.

In addition, through silicon vias (TSVs) are formed through the siliconsubstrate for coupling multiple integrated circuit chips to form astacked semiconductor device. Such a stacked semiconductor device isformed to provide an integrated circuit with high capacity and low area.

With any type of via, a conductive line is desired to be formed onto thevia with high quality of contact. Such a high quality contact is desiredfor connection between the via and the conductive line with lowresistance and high current capacity.

SUMMARY OF THE INVENTION

Accordingly, a conductive structure is formed over a planar portion of avia structure to ensure a high quality connection between the conductivestructure and the via structure.

According to an aspect of the present invention, a semiconductor deviceincludes a via structure and a conductive structure. The via structurehas a surface with a planar portion and a protrusion portion. Theconductive structure is formed over at least part of the planar portionand not over at least part of the protrusion portion of the viastructure.

In an example embodiment of the present invention, the conductivestructure is formed only onto the planar portion and not onto any of theprotrusion portion. For example, the conductive structure is formed ontofrom about 5% to about 80% of an area of the surface of the viastructure.

In another example embodiment of the present invention, thesemiconductor device further includes a buffer layer formed onto theprotrusion portion of the via structure. Furthermore, a dielectric layeris formed over the protrusion portion of the via structure and surroundsthe conductive structure.

In a further example embodiment of the present invention, the viastructure is a TSV (through silicon via) formed within an openingthrough at least one dielectric layer and a semiconductor substrate. Forexample, the TSV includes an insulation layer formed at a wall of theopening, and includes a barrier layer formed on the insulation layerwithin the opening. The TSV also includes a conductive fill formedwithin the opening with the barrier layer surrounding at least a portionof the conductive fill.

In another example embodiment of the present invention, the TSV furtherincludes a center fill formed within the opening with the conductivefill surrounding at least a portion of the center fill. The center fillhas a thermal expansion coefficient that is lower than that of theconductive fill such that the protrusion portion is formed as a ringwith minimized height of the protrusion portion.

In a further example embodiment of the present invention, the TSV iscoupled to a contact structure of another semiconductor device forforming a stacked semiconductor device. For example, the stackedsemiconductor device is a memory device.

In another example embodiment of the present invention, thesemiconductor device further includes another conductive structureformed onto at least part of the planar portion and not onto theprotrusion portion of the via structure. In addition, a linkingstructure couples the conductive structures.

In a further example embodiment of the present invention, the conductivestructure includes an opening formed over the at least part of theprotrusion portion of the via structure.

In another example embodiment of the present invention, thesemiconductor device further includes another via structure having arespective surface with a respective planar portion and a respectiveprotrusion portion. The conductive structure is formed onto the planarportions and not onto the protrusion portions of the multiple viastructures.

In a further example embodiment of the present invention, thesemiconductor device further includes a plurality of via structures anda plurality of conductive structures. Each via structure has arespective surface with a respective planar portion and a respectiveprotrusion portion. Each conductive structure is formed onto the planarportions and not onto the protrusion portions of a respective set of atleast two of the multiple via structures. In addition, a linkingstructure couples the plurality of conductive structures.

According to another aspect of the present invention, a stackedsemiconductor device includes a first integrated circuit chip and asecond integrated circuit chip. The first integrated circuit chipincludes a via structure and a conductive structure. The via structurehas a surface with a planar portion and a protrusion portion. Theconductive structure is formed over at least part of the planar portionand not over at least part of the protrusion portion of the viastructure. The second integrated circuit chip includes a contactstructure coupled to the via structure of the first integrated circuitchip.

The conductive structure and the via structure of the first integratedcircuit chip of the stacked semiconductor device may be formed withfurther embodiments as described above.

According to a further aspect of the present invention, a semiconductordevice includes a via structure formed through a semiconductorsubstrate. The via structure has a surface with a center portion and anouter portion. The semiconductor substrate also includes a conductivestructure formed over at least part of the outer portion and not over atleast part of the center portion of the via structure.

In an example embodiment of the present invention, the center portion isformed to be flat with the outer portion such that the center portion isplanar with the outer portion of the via structure. In an alternativeembodiment of the present invention, the center portion protrudes fromthe outer portion of the via structure.

According to a further aspect of the present invention, a method forfabricating a semiconductor device includes a step of forming a viastructure having a surface with a planar portion and a protrusionportion. In addition, the method also includes the step of forming aconductive structure over at least part of the planar portion and notover at least part of the protrusion portion of the via structure.

In another embodiment of the present invention, the method furtherincludes the steps of heating the via structure to form an initialprotrusion portion of the via structure and planarizing the initialprotrusion portion to decrease a height of the resulting protrusionportion of the via structure before forming the conductive structure.

The conductive structure and the via structure according to the methodembodiments may be formed with further embodiments as described above.

In this manner, the conductive structure is formed onto a planar portionof the via structure and not onto the protrusion portion of the viastructure. Thus, the conductive structure connects to the via structurewith low resistance and high current capacity.

These and other features and advantages of the present invention will bebetter understood by considering the following detailed description ofthe invention which is presented with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional view of a semiconductor device having viaand conductive structures, according to an example embodiment of thepresent invention;

FIG. 1B is a top view of the semiconductor device of FIG. 1A, accordingto an example embodiment of the present invention;

FIGS. 2, 3, 4, 5, 6, 7, 8, and 9 are cross-sectional views illustratingsteps during fabrication of the semiconductor device of FIGS. 1A and 1B,according to an example embodiment of the present invention;

FIGS. 10 and 11 are cross-sectional views illustrating further stepsduring fabrication of the semiconductor device of FIGS. 1A and 1B,according to another example embodiment of the present invention;

FIG. 12 is a cross-sectional view of a stacked semiconductor devicehaving a TSV (through silicon via) structure formed similarly to FIG.1A, according to an example embodiment of the present invention;

FIGS. 13, 14, 15, 16, and 17 are cross-sectional views illustratingsteps during fabrication of the stacked semiconductor device of FIG. 12,according to an example embodiment of the present invention;

FIGS. 18A and 18B are top views for illustrating formation of aconductive structure with an opening over a via structure, according toexample embodiments of the present invention;

FIGS. 19 and 20 are top views for illustrating formation of multipleconductive structures onto multiple via structures, according to exampleembodiments of the present invention;

FIG. 21 is a cross-sectional view including additional conductivestructures formed onto a via structure in a semiconductor device,according to an example embodiment of the present invention;

FIGS. 22 and 23 are cross-sectional and top views illustrating asemiconductor device having a via structure with a center fill,according to an example embodiment of the present invention;

FIGS. 24 and 25 are cross-sectional views illustrating steps duringfabrication of the semiconductor device of FIGS. 22 and 23, according toan example embodiment of the present invention;

FIGS. 26, 27, and 28 are top views of a semiconductor device havingmultiple conductive structures formed onto multiple via structures,according to example embodiments of the present invention;

FIGS. 29, 30, and 31 show block diagrams of systems, each having astacked semiconductor device, according to example embodiments of thepresent invention;

FIGS. 32 and 33 show cross-sectional views of a semiconductor devicehaving center and outer portions that are planar with each-other,according to an example embodiment of the present invention; and

FIGS. 34 and 35 show top and cross-sectional views of a semiconductordevice having an annular via structure, according to an exampleembodiment of the present invention.

The figures referred to herein are drawn for clarity of illustration andare not necessarily drawn to scale. Elements having the same referencenumber in FIGS. 1A, 1B, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18A, 18B, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,32, 33, 34, and 35 refer to elements having similar structure and/orfunction, unless stated other-wise.

DETAILED DESCRIPTION

Various example embodiments are described more fully hereinafter withreference to the accompanying drawings, in which example embodiments areshown. The present inventive concept may, however, be embodied in manydifferent forms and should not be construed as limited to the exampleembodiments set forth herein. Rather, these example embodiments areprovided so that this description will be thorough and complete, andwill fully convey the scope of the present inventive concept to thoseskilled in the art. In the drawings, the sizes and relative sizes oflayers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numerals refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present inventive concept.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” “over” and the like, may be used herein for ease of descriptionto describe one element or feature's relationship to another element(s)or feature(s) as illustrated in the figures. It will be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures.

For example, if the device in the figures is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” or “over” the other elements or features. Thus, theexemplary term “below” can encompass both an orientation of above andbelow. The device may be otherwise oriented (rotated 90 degrees or atother orientations), and the spatially relative descriptors used hereininterpreted accordingly.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent inventive concept. As used herein, the singular forms “a,” “an”and “the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise.

It will be further understood that the terms “comprises” and/or“comprising,” when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations of idealized example embodiments (andintermediate structures). As such, variations from the shapes of theillustrations as a result, for example, of fabrication techniques and/ortolerances, are to be expected. Thus, example embodiments should not beconstrued as limited to the particular shapes of regions illustratedherein but are to include deviations in shapes that result, for example,from variations during fabrication.

For example, an implanted region illustrated as a rectangle will,typically, have rounded or curved features and/or a gradient of implantconcentration at its edges rather than a binary change from implanted tonon-implanted region. Likewise, a buried region formed by implantationmay result in some implantation in the region between the buried regionand the surface through which the implantation takes place. Thus, theregions illustrated in the figures are schematic in nature and theirshapes are not intended to illustrate the actual shape of a region of adevice and are not intended to limit the scope of the present inventiveconcept.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive concept belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, example embodiments will be explained in detail withreference to the accompanying drawings.

FIG. 1A is a cross-sectional view of a semiconductor device having viaand conductive structures, according to an example embodiment of thepresent invention. FIG. 1B is a top view of the semiconductor device ofFIG. 1A, according to an example embodiment of the present invention.

Referring to FIGS. 1A and 1B, a first circuit pattern 12 is formed on afirst substrate 10. The first substrate 10 is comprised of asemiconductor material, such as single crystalline silicon for example.The first circuit pattern 12 includes transistors, diodes, and the likefor forming an integrated circuit for example.

A first insulating interlayer 14 is formed to surround the first circuitpattern 12 on the first substrate 10. A lower wiring 16 comprised of aconductive material such as doped polysilicon or a metal for example isformed to be electrically connected to the first circuit pattern 12. Inan example embodiment, the lower wiring 16 has a top surface that iscoplanar with a top surface of the first insulating interlayer 14.

Further referring to FIGS. 1A and 1B, a via hole 20 is formed as anopening through the first insulating interlayer 14 and through at leasta portion of the first substrate 10. The present invention may bepracticed with formation of a plurality of via holes 20. An insulationlayer pattern 22 a is formed on an inner wall of the via hole 20. Theinsulation layer pattern 22 a electrically insulates the first substrate10 from a through silicon via (TSV) contact 28 comprised of a conductivematerial.

The TSV structure 28 is an example via structure for being coupled to aconductive line structure. However, the present invention may bepracticed with any type of via structure for being connected to aconductive line structure.

A barrier layer pattern 24 a is formed on the insulation layer pattern22 a. The barrier layer pattern 24 a is comprised of a metal or a metalnitride such as tantalum, tantalum nitride, titanium, titanium nitride,ruthenium, cobalt, nickel, nickel boride, tungsten nitride, and thelike, in an example embodiment of the present invention. Such materialmay be used alone or in a combination thereof.

A conductive fill 26 a is formed to fill a remaining portion of the viahole 20 surrounded by the barrier layer pattern 24 a. The conductivefill 26 a is comprised of a metal having a low resistance and a thermalexpansion coefficient equal to or more than about 1.5 times that ofsilicon, according to an example embodiment of the present invention.For example, the conductive fill 26 a is comprised of copper, aluminum,gold, indium, nickel, and the like, alone or in a combination thereof.In an example present embodiment, the conductive fill 26 a is comprisedof copper. The conductive fill 26 a and the barrier layer pattern 24 aform the TSV structure 28 as an example via structure.

The via structure 28 includes a surface including an outer portion and acenter portion 27 facing up away from the substrate 10 as shown in thetop view of FIG. 1B. Referring to FIGS. 1A and 1B, the outer portion isdisposed adjacent at least one surrounding material such as theinsulation layer pattern 22 a, and the center portion 27 is surroundedby the outer portion.

Referring to FIGS. 1A and 1B, the outer portion of the via structure 28is comprised of the barrier layer pattern 24 a and a portion of theconductive fill 26 a having a top surface that is parallel with asurface of the substrate 10. Another words, the outer portion of the viastructure 28 is comprised of the barrier layer pattern 24 a and theportion of the conductive fill 26 a having the top surface that iscoplanar with the surrounding first insulating interlayer 14, in anexample embodiment of the present invention. Thus, such an outer portionof the via structure 28 is also referred to as a planar portion of thevia structure 28.

The via structure 28 further includes the center portion 27 that isprotruded from the outer portion of the via structure 28. Another words,the center portion 27 includes parts of a top surface (shown in the topview of FIG. 1B) of the conductive fill 26 a that extends further fromthe plane of the outer portion and the plane of surrounding firstinsulating interlayer 14. Thus, such a center portion of the viastructure 28 is also referred to as a protrusion portion of the viastructure 28. When the conductive fill 26 a is comprised of copper, theprotrusion portion 27 of the via structure 28 may be formed by thermalexpansion of such copper during subsequent fabrication of thesemiconductor device of FIGS. 1A and 1B.

In the example embodiment of FIGS. 1A and 1B, the conductive fill 26 ahas a height H of from about 10 μm to about 100 μm. In an examplepreferred embodiment, the height H is in a range of from about 30 μm toabout 80 μm. In addition, the conductive fill 26 a has a diameter D offrom about 1 μm to about 15 μm. In an example preferred embodiment, thediameter D is in a range of from about 1 μm to about 10 μm.

Further referring to FIGS. 1A and 1B, a buffer layer 30 is formed ontothe TSV structure 28 and the first insulating interlayer 14. A portionof the buffer layer 30 remains on the protrusion portion 27 of the viastructure 28. The buffer layer 30 prevents the conductive material ofthe TSV structure 28 from diffusing into other structures.

The buffer layer 30 is comprised of silicon nitride, siliconcarbonitride (SiCN), silicon carbo-oxynitride (SiCON), and the like,alone or in a combination thereof, in an example embodiment of thepresent invention. The buffer layer 30 has a thickness of from about 300Å to about 1000 Å, in an example embodiment of the present invention.

A first inter-metal dielectric layer 32 is formed on the buffer layer30, and is comprised of a material having a low dielectric constant suchas silicon oxide, carbon-doped silicon oxide, and the like for example.A plurality of conductive lines 36 is formed through the firstinter-metal dielectric layer 32 and the buffer layer 30. The conductivelines 36 are an example conductive structure contacting at least a partof the outer planar portion of the TSV structure 28.

If the conductive lines 36 contact more than about 80% of the entire topsurface of the TSV structure 28, then the conductive lines 36 maycontact the protrusion 27. If the conductive lines 36 contact less thanabout 5% of the entire top surface of the TSV structure 28, such a smallcontact area may result in insufficient current-flow through such acontact area. Thus, the conductive lines 36 are formed to contact fromabout 5% to about 80% of the entire top surface of the TSV structure 28in an example embodiment of the present invention. Some of theconductive lines 36 contact a top surface of the lower wiring 16 asillustrated in FIG. 1A.

In the example embodiment of FIG. 1B, portions of two parallelconductive lines 36 contact the outer planar portion of the TSVstructure 28. In addition, no part of the conductive lines 36 contactsthe center protrusion portion 27 of the TSV structure 28, according toan aspect of the present invention.

The conductive lines 36 may be formed with a barrier layer (not shown)and a metal layer comprised of a metal having a low resistance and athermal expansion coefficient of about 1.5 times that of silicon. Forexample, such a metal layer is comprised of copper, aluminum, gold,indium, nickel, and the like.

A second inter-metal dielectric layer 38 is formed on the firstinter-metal dielectric layer 32 and the conductive lines 36. First upperwirings 40 are formed through the second inter-metal dielectric layer 38and are electrically connected to the conductive lines 36. Thus, theupper wirings 40 form an example linking structure for connecting theconductive lines 36. Additional insulating inter-layers (not shown)and/or wirings (not shown) may be formed.

FIGS. 2, 3, 4, 5, 6, 7, 8, and 9 are cross-sectional views illustratingsteps during fabrication of the semiconductor device of FIGS. 1A and 1B,according to an example embodiment of the present invention.

Referring to FIG. 2, the first circuit pattern 12 comprised oftransistors, diodes, and the like for fabricating an integrated circuitis formed on the first substrate 10. The first insulating interlayer 14is formed on the first substrate 10 to surround the first circuitpattern 12. The lower wiring 16 is formed through the first insulatinginterlayer 14. Thereafter, an etch stop layer 18 is formed on the firstinsulating interlayer 14 and the lower wiring 16. Accordingly, afront-end-of-the-line (FEOL) process is completed in FIG. 2.

Subsequently in FIG. 3, a photoresist mask (not shown) having athickness of from about 2 μm to about 5 μm is formed on the etch stoplayer 18. The etch stop layer 18, the first insulating interlayer 14,and the first substrate 10 are then patterned using such an photoresistmask to form a via hole 20 through the etch stop layer 18, the firstinsulating interlayer 14, and a portion of the first substrate 10. In anexample embodiment of the present invention, a plurality of via holes 20is formed for a corresponding plurality of TSV structures. Thereafter,the photoresist mask is removed to result in the structures of FIG. 3.

Further referring to FIG. 3, an insulation layer 22 is formed on aninner wall of the via hole 20 and on the etch stop layer 18. Theinsulation layer 22 is comprised of silicon oxide or carbon-dopedsilicon oxide in an example embodiment of the present invention. Forexample, the insulation layer 22 is formed using tetraethylorthosilicate (TEOS) or ozone TEOS having good step coveragecharacteristics. The insulation layer 22 is formed by a plasma oxidationprocess or a chemical vapor deposition (CVD) process in an exampleembodiment of the present invention.

Thereafter referring to FIG. 4, a barrier layer 24 is formed on theinsulation layer 22. The barrier layer 24 is comprised of a metal or ametal nitride such as tantalum, tantalum nitride, titanium, titaniumnitride, ruthenium, cobalt, nickel, nickel boride, tungsten nitride, andthe like, alone or in a combination thereof in an example embodiment ofthe present invention. The barrier layer 24 has a thickness of fromabout 100 Å to about 3000 Å in an example embodiment of the presentinvention.

A seed layer (not shown) may be formed on the barrier layer 24 forproviding an electrode for forming a conductive layer 26 there-from.Such a layer is comprised of copper formed by a physical vapordeposition (PVD) process, in an example embodiment of the presentinvention.

The conductive layer 26 is formed from the seed layer to fill theremaining portion of the via hole 20 after the seed layer has beenformed on the barrier layer 24. The conductive layer 26 is comprised ofa metal having a low resistance, such as copper for example, formed byan electroplating process, an electroless plating process, anelectrografting process, a PVD process, and the like. A further heattreatment process may be performed with the conductive layer 26.

The conductive layer 26 may be comprised of other metals having athermal expansion coefficient more than about 2 times that of silicon.For example, the conductive layer 26 is comprised of aluminum, gold,indium, nickel, and the like.

Subsequently referring to FIG. 5, upper portions of the conductive layer26, the barrier layer 24, the insulation layer 22, and the etch stoplayer 18 are planarized by a chemical mechanical polishing (CMP) processand/or an etch back process until the first insulating interlayer 14 isexposed. Such a planarization results in forming the conductive fill 26a, the barrier layer pattern 24 a, and the insulation layer pattern 22 aremaining within the via hole 20. The conductive fill 26 a and thebarrier layer pattern 24 a form the TSV structure 28. The etch stoplayer 18 may be completely removed in the planarization process.Alternatively, a portion of the etch stop layer 18 may remain after theplanarization process.

Thereafter referring to FIG. 6, a buffer layer 30 is formed on the firstinsulating interlayer 14 to cover the exposed top surface of theinsulation layer pattern 22 a, the TSV structure 28, and the lowerwiring 16. The buffer layer 30 is comprised of an insulating materialsuch as silicon nitride, silicon carbonitride (SiCN), siliconcarbo-oxynitride (SiCON), and the like, alone or in a combinationthereof with a thickness of from about 300 Å to about 1000 Å, in anexample embodiment of the present invention. The buffer layer 30prevents the conductive material of the TSV structure 28 from diffusingto other structures.

Subsequently referring to FIG. 7, the first inter-metal dielectric layer32 is formed on the buffer layer 30 and the first insulating interlayer14. The first inter-metal dielectric layer 32 is comprised of siliconoxide or carbon-doped silicon oxide, in an example embodiment of thepresent invention. During formation of the buffer layer 30 and the firstinter-metal dielectric layer 32, the conductive fill 26 a may thermallyexpand to result in formation of the center protrusion portion 27.

Further referring to FIG. 7, the first inter-metal dielectric layer 32and the buffer layer 30 are patterned to form a first opening 34exposing at least a part of the outer planar portion of the top surfaceof the TSV structure 28 and exposing the lower wiring 16. The firstopening 34 is formed to have a line shape, in an example embodiment ofthe present invention. The part of the top surface of the TSV structure28 that is exposed through the first opening 34 is from about 5% toabout 80% of such a top surface of the TSV structure 28.

In an example embodiment of the present invention, two parallel firstopenings 34 are formed over parts of the outer planar portion of the topsurface of the TSV structure 28. Accordingly, portions of the bufferlayer 30 and the first inter-metal dielectric layer 32 remain over thecenter protrusion portion 27.

Thereafter referring to FIG. 8, a barrier layer (not shown) and aconductive material are formed into the first openings 34 and ontoexposed portions of the TSV structure 28, the lower wiring 16, and thefirst inter-metal dielectric layer 32. Thereafter another planarizationprocess is performed on the upper portions of such a barrier layer andsuch a conductive material until the first inter-metal dielectric layer32 is exposed such that the conductive lines 36 are formed to becontained in the first openings 34.

According to an aspect of the present invention, the conductive lines 36do not contact the center protrusion portion 27 of the TSV structure 28.The height and position of the protrusion portion 27 depends on thediameter and the depth of the via hole 20.

When the via hole 20 has a diameter and a depth smaller than aboutseveral thousand angstroms, the conductive fill 26 a within the via hole20 has a small volume such that the protrusion portion 27 issufficiently small. For example, the lower wiring 16 has a diametersmaller than about several thousand angstroms such that the lower wiring16 does not thermally expand significantly during the formation of thebuffer layer 30 and the first inter-metal dielectric layer 32.

In contrast, the TSV structure 28 is relatively larger than otherwirings such that the TSV structure 28 thermally expands significantlyduring formation of the buffer layer 30 and the first inter-metaldielectric layer 32. For example, the conductive fill 26 a has adiameter of from about 1 μm to about 15 μm and a height of from about 10μm to about 100 μm such that the conductive fill 26 a thermally expandssignificantly.

When the buffer layer 30 and the first inter-metal dielectric layer 32are formed, the sidewall of the conductive fill 26 a that contacts thebarrier layer pattern 24 a does not expand significantly because ofrelatively high adhesion between such materials. Thus, just the centralportion of the conductive fill 26 a expands to form the centerprotrusion portion 27.

The adhesion between the conductive fill 26 a and the barrier layerpattern 24 a is low when the conductive fill 26 a has a diameter of fromabout 15 μm to about 50 μm. In that case, the conductive fill 26 aexpands with the entire top surface of the conductive fill 26 a beingextended to form the protrusion.

Subsequently referring to FIG. 9, a second inter-metal dielectric layer38 is formed on the first inter-metal dielectric layer 32 and theconductive lines 36. The first upper wiring 40 is formed through thesecond inter-metal dielectric layer 38 to be electrically connected tothe conductive lines 36. In particular, second openings (not shown) areformed through the second inter-metal dielectric layer 38, and a barrierlayer (not shown) and a conductive material such as copper for exampleare formed to fill such openings to form the first upper wiring 40.

In addition, further insulating inter-layers (not shown) and additionalwirings (not shown) may be formed after FIG. 9. In this manner, theconductive lines 36 as an example conductive structure are formed ontothe outer planar portion of the top surface of the TSV structure 28 andnot onto the center protrusion portion 27. Thus, the conductive lines 36are formed onto the TSV structure 28 with minimized contact resistance.

In addition referring to FIG. 32, the present invention may also bepracticed with an alternative through silicon via (TSV) structure 28 aformed with the insulation layer pattern 22 a, the barrier layer pattern24 a, and the conductive fill 26 a. In FIG. 32, the TSV structure 28 ahas a center portion 27 b that is planar (i.e., flat) with an outerportion 27 a of the top surface of the TSV structure 28 a.

In FIG. 32, the outer portion 27 a of the top surface of the TSVstructure 28 a is adjacent the insulation layer pattern 22 a. The centerportion 27 b of the top surface of the TSV structure 28 a is surroundedby the outer portion 27 a. Subsequently referring to FIG. 33, theconductive lines 36 a are formed onto only the outer portion 27 a andnot onto the center portion 27 b, according to an embodiment of thepresent invention.

Alternatively referring to FIGS. 34 and 35, the present invention mayalso be practiced with an annular through silicon via (TSV) structure 28b that is formed as a ring shape. FIG. 35 is a cross-sectional view ofFIG. 34 across the line I-I. The TSV structure 28 b is formed with theinsulation layer pattern 22 a, the barrier layer pattern 24 a, and theconductive fill 26 a filling a via hole formed as a ring shape.

The TSV structure 28 b has an outer portion 27 c of the top surface ofthe TSV structure 28 a that is adjacent the insulation layer pattern 22a. The center portion 27 d of the top surface of the TSV structure 28 ais surrounded by the outer portion 27 c and has a protrusion of theconductive fill 26 a shaped as a ring. In the example of FIGS. 34 and35, a conductive line would be formed onto at least a part of the outerportion 27 c and not onto the center protrusion portion 27 d of theannular TSV structure 28 b, according to an embodiment of the presentinvention.

FIGS. 10 and 11 are cross-sectional views illustrating further stepsduring fabrication of the semiconductor device of FIGS. 1A and 1B,according to another example embodiment of the present invention. FIGS.10 and 11 illustrate additional steps for forming the via structure ofFIGS. 1, 2, 3, 4, 5, 6, 7, 8, and 9 with like reference numeralsreferring to like elements.

Steps illustrated is FIGS. 2, 3, 4, and 5 are performed to form the TSVstructure 28 having the conductive fill 26 a and the barrier layerpattern 24 a. Subsequently referring to FIG. 10, a heat treatmentprocess is performed such that an initial protrusion is formed at a topsurface of the TSV structure 28 from thermal expansion of the conducivefill 26 a. In FIG. 10, the TSV structure 28 c has the expandedconductive fill 26 c.

If such a heat treatment process is performed at a temperature of lessthan about 100° C., the TSV structure 28 may not be sufficientlyexpanded. When the heat treatment process is performed at a temperatureof more than about 600° C., the TSV structure 28 may be deteriorated.Thus, the heat treatment process of FIG. 10 is performed at atemperature of from about 100° C. to about 600° C.

Thereafter referring to FIG. 11, the initial center protrusion portionof the top surface of the expanded TSV structure 28 c is planarized by aCMP process and/or an etch back process to form the TSV structure 28again having a planar top surface after removal of the initial centerprotrusion portion of FIG. 10. In this manner, the TSV structure 28 hasalready been thermally expanded such that the TSV structure 28 may notthermally expand as much during subsequent processes for forming thebuffer layer 30 and the first inter-metal dielectric layer 32. AfterFIG. 11, the process steps of FIGS. 6, 7, 8, and 9 are performed tocomplete the semiconductor device.

FIG. 12 is a cross-sectional view of a stacked semiconductor devicehaving a TSV (through silicon via) structure formed similarly to FIG.1A, according to an example embodiment of the present invention.Referring to FIG. 12, the stacked semiconductor device includes a firstintegrated circuit chip 150, a second integrated circuit chip 152, asolder 50, and a contact structure 112. The first integrated circuitchip 150 includes a memory device or a logic device fabricated therein,according to an example embodiment of the present invention.Alternatively, the first integrated chip 150 may include an imagingdevice fabricated therein.

The first integrated circuit chip 150 is formed substantially similar asthe semiconductor device of FIGS. 1A and 1B, except that the bottomsurface of a TSV structure 128 a and an insulation layer pattern 122 bare exposed at the bottom surface of the first substrate 10 a. The TSVstructure 128 a and the insulation layer pattern 122 b of FIG. 12 areformed similar as the TSV structure 28 and the insulation layer pattern22 a of FIGS. 1A and 1B.

Additionally, a first protection layer 46 is further formed on a secondupper wiring 44 and a third inter-metal dielectric layer 42. The solder50 is formed through the first protection layer 46.

The first integrated circuit chip 150 includes the first substrate 10 a,the first circuit pattern 12, the lower wiring 16, the first insulatinginterlayer 14, and the insulation layer pattern 122 b. Additionally, thefirst integrated circuit chip 150 includes the TSV structure 128 a andthe conductive lines 36. The TSV structure 128 a is formed through thefirst insulating interlayer 14 and the first substrate 10 a. Theconductive lines 36 are formed onto the outer planar portion of the topsurface of the TSV structure 128 a and not onto the center protrusionportion of such a top surface, similar to FIGS. 1A and 1B. Theconductive lines 36 are surrounded by the first inter-metal dielectriclayer 32.

The first and second upper wirings 40 and 44 and the second and thirdinter-metal dielectric layers 38 and 42 are further included in thefirst integrated circuit chip 150. The first protection layer 46 coversthe second upper wiring 44, and the solder 50 contacts the second upperwiring 44 through the first protection layer 46.

The first substrate 10 a is comprised of single crystalline silicon andhas a thickness of from about 10 μm to about 100 μm. The first substrate10 a has a bottom surface that is coplanar with the bottom surface ofthe TSV structure 128 a. The present invention may also be practicedwith the bottom surface of the TSV structure 128 a being protruded fromthe bottom surface of the first substrate 10 a.

The via hole 20 is formed through the first substrate 10 a. Theinsulation layer pattern 122 b is formed on the sidewall of the via hole20. A barrier layer pattern 124 b and a seed layer pattern (not shown)are formed on the insulation layer pattern 122 b. A conductive fill 126a is formed to fill the remaining portion of the via hole 20 from theseed layer pattern.

The conductive fill 126 a is comprised of a metal having a lowresistance and a thermal expansion coefficient of about 2 times of thatof silicon, in an example embodiment of the present invention. Forexample, the conductive fill 126 a is comprised of copper, aluminum,gold, indium, nickel, and the like. In an example embodiment of thepresent invention, the conductive fill 126 a is comprised of copper.

The TSV structure 128 a is electrically connected to an electricalsignal pad, a pin power signal pad, a power amp module, etc., fortransmission of an electrical signal between the first and secondintegrated circuit chips 150 and 152. The second and third inter-metaldielectric layers 38 and 42 are sequentially formed on the firstinter-metal dielectric layer 32. The conductive lines 36 and the firstand second upper wirings 40 and 44 are formed through such dielectriclayers 38 and 42.

The second upper wiring 44 as the highest upper wiring may be alsoreferred to as a first pad electrode 44. The first protection layer 46covering the second upper wiring 44 is formed on the third inter-metaldielectric layer 42. The first protection layer 46 is comprised ofpolyimide, according to an example embodiment of the present invention.

The solder 50 is electrically connected to the first pad electrode 44and may contact a printed circuit board (PCB) (not shown).Alternatively, the present invention may be practiced with the first pad44 being electrically connected to a lead frame (not shown) by wirebonding.

The second integrated chip 152 is comprised of a second substrate 100, asecond circuit pattern 102, wirings 104, second insulating inter-layers106, and a second pad electrode 108. The present invention may bepracticed with the second integrated circuit chip 152 including elementssubstantially similar as those of the first integrated circuit chip 150,or including elements different from those of the first integratedcircuit chip 150.

The second pad electrode 108 is electrically connected to the wirings104 and is formed above the second insulating inter-layers 106. Thesecond pad electrode 108 is electrically connected to the TSV structure128 a formed in the first substrate 10 a. A second protection layer 110is formed to cover the second pad electrode 108 above the secondinsulating inter-layers 106. The second protection layer 110 iscomprised of polyimide, according to an example embodiment of thepresent invention.

The contact structure 112 is comprised of a conductive material formedthrough the second protection layer 110 between the second pad electrode108 and the TSV structure 128 a of the first integrated circuit chip150. The contact structure 112 is comprised of silver solder paste in anexample embodiment of the present invention.

The stacked semiconductor device includes the first and secondintegrated circuit chips 150 and 152 that are stacked together for beingelectrically connected with the TSV structure 128 a. The TSV structure128 a and the conductive lines 36 have good adhesion characteristics forhigh speed signal transfer between the first and second integratedcircuit chips 150 and 152 resulting in good electrical characteristicsand high reliability of the stacked semiconductor device of FIG. 12. Thesemiconductor device of FIG. 12 may have other chips (not shown) thatare sequentially stacked with the first and second integrated circuitchips 150 and 152 and that are electrically connected with TSVstructures therein.

FIGS. 13, 14, 15, 16, and 17 are cross-sectional views illustratingsteps during fabrication of the stacked semiconductor device of FIG. 12,according to an example embodiment of the present invention. Referringto FIG. 13, the first circuit pattern 12 is formed on the firstsubstrate 10, and the first insulating interlayer 14 is formed on thefirst substrate 10 to surround the first circuit pattern 12. The lowerwiring 16 is formed through the first insulating interlayer 14.

The first insulating interlayer 14 and the first substrate 10 arepatterned to form the via holes 20 therein. The insulation layer pattern122 a and the TSV structure 128 including the barrier layer pattern 124a and the conductive fill 126 a are formed in the via holes 20 similarlyas in FIG. 5. The conductive fill 126 a has a center protrusion portion27 similar as in FIG. 9.

Referring to FIG. 14, the buffer layer 30 is formed on the firstinsulating interlayer 14 and the TSV structure 128. The firstinter-metal dielectric layer 32 is formed on the buffer layer 30. Theconductive line structures 36 are formed through the first inter-metaldielectric layer 32 and the buffer layer 30 to be electrically connectedto the outer planar portion of the TSV structure 128 and onto the lowerwiring 16.

The conductive lines 36 do not contact the center protrusion portion 27of the TSV structure 128, similar to FIG. 9. The second and thirdinter-metal dielectric layers 38 and 42 and the first and second upperwirings 40 and 44 are formed on the first inter-metal dielectric layer32 and the conductive lines 36 similarly as in FIGS. 6, 7, 8, and 9.

Thereafter referring to FIG. 15, the first protection layer 46 is formedon the third inter-metal dielectric layer 42 to cover the second upperwiring 44. The first protection layer 46 is comprised of polyimide,according to an example embodiment of the present invention. The firstprotection layer 46 is patterned to form a third opening 48 exposing thesecond upper wiring 44.

Bottom portions of the first substrate 10, the insulation layer pattern122 a, the barrier layer pattern 124 a, and the conductive fill 126 amay be removed by grinding for exposing a bottom surface of theconductive fill 126 a. With such grinding, the thickness of the firstsubstrate 10 a is reduced. The remaining conductive fill 126 a and thebarrier layer pattern 124 b define the TSV structure 128 a. Theinsulation layer pattern 122 b surrounds such a TSV structure 128 a inthe via hole.

With such grinding, the bottom surface of the conductive fill 126 a iscoplanar with the bottom surface of the first substrate 10 a. However,the present invention may also be practiced with the bottom surface ofthe conductive fill 126 a being protruded from the bottom surface of thefirst substrate 10 a.

The insulation layer pattern 122 b has a cylindrical shape on thesidewall of the via hole 20, and the barrier layer pattern 124 b has acylindrical shape on the sidewall of the insulation layer pattern 122 b.The barrier layer pattern 124 b surrounds the conductive fill 126 a.Subsequently referring to FIG. 16, the solder 50 is formed in the thirdopening 48 such that the first integrated circuit chip 150 including theTSV structure 128 a is completed.

Referring to FIG. 17, the second integrated circuit chip 152 is formedwith the second substrate 100 and includes the second circuit pattern102, the wirings 104, and the plurality of second insulatinginter-layers 106. The second pad electrode 108 is formed above thesecond insulating inter-layers 106 to be electrically connected to thewirings 104. The second pad electrode 108 is formed to be facing the TSVstructure 128 a of the first substrate 10 a.

The second protection layer 110 is formed on the second insulatinginter-layers 106 to cover the second pad electrode 108. The secondprotection layer 110 is patterned to form a fourth opening exposing thesecond pad electrode 108. The contact structure 112 is formed in thefourth opening to be electrically connected to the second pad electrode108. Referring back to FIG. 12, the bottom surface of the TSV structure128 a of the first substrate 10 a and the contact structure 112 of thesecond substrate 100 are attached to each other for completing thestacked semiconductor device including the first and second integratedcircuit chips 150 and 152.

FIGS. 18A and 18B are top views for illustrating formation of aconductive structure with an opening over the via structure, accordingto example alternative embodiments of the present invention. Thesemiconductor devices of FIGS. 18A and 18B are formed similar as inFIGS. 1A and 1B, except for the shape of the conductive line structures.

Referring to FIGS. 18A and 18B, first and second conductive lines 60 aand 60 b have first and second openings 62 a and 62 b, respectively,each exposing the center protrusion portion 27 of the TSV structure 28.Each of the conductive lines 60 a and 60 b has a width equal to orlarger than a diameter of the TSV structure 28. The conductive lines 60a and 60 b do not contact the center protrusion portion 27 but contactthe outer planar portion of the TSV structure 28.

The openings 62 a and 62 b have a size depending on the size of theprotrusion portion 27. The first opening 62 a has a size larger thanthat of the protrusion portion 27 and smaller than that of the TSVstructure 28. The second opening 62 b has a size larger than that of theprotrusion portion 27 and further extends along a direction of theconductive line 60 b. The second opening 62 b also exposes parts of thetop surfaces of the barrier layer pattern 24 a, the insulation layerpattern 22 a, and the first insulating interlayer 14.

In either case, each of the conductive lines 60 a and 60 b contacts fromabout 5% to about 80% of the top surface of the TSV structure 28. Thesemiconductor devices of FIGS. 18A and 18B may be formed similarly as inFIGS. 2, 3, 4, 5, 6, and 7, except for the position and shape of thefirst openings 34. Furthermore, the processes of FIGS. 8 and 9 aresubsequently performed to complete the semiconductor devices of FIGS.18A and 18B.

FIGS. 19 and 20 are top views for illustrating formation of multipleconductive structures onto multiple via structures, according to exampleembodiments of the present invention. The semiconductor device of FIG.19 is formed similar to that of FIGS. 1A and 1B, except for the shape ofthe conductive lines formed onto the TSV structures.

Referring to FIG. 19, a conductive line 64 extending along a directionover multiple TSV structures 28 a and 28 b are divided into multiplepieces along that direction. Each piece of the conductive line 64contacts the outer planar portions of the top surfaces of at least oneof the TSV structures 28 a and 28 b. Such pieces of the conductive line64 are electrically connected to each other by the TSV structures 28 aand 28 b.

In an example embodiment of the present invention in FIG. 19, theconductive line 64 is divided into three pieces. One piece of theconductive line 64 contacts the outer planar portions of the topsurfaces of both TSV structures 28 a and 28 b. Another piece of theconductive line 64 contacts the outer planar portion of the top surfaceof the first TSV structure 28 a, and the other piece of the conductiveline 64 contacts the outer planar portion of the top surface of thesecond TSV structure 28 b.

Such pieces of the conductive line 64 contact from about 5% to about 80%of the entire top surfaces of the TSV structures 28 a and 28 b. Thesemiconductor device of FIG. 19 may be formed similar to those of FIGS.2, 3, 4, 5, 6, 7, 8, and 9, except for the position and shape of thefirst openings 34.

The semiconductor device of FIG. 20 is also similar to that of FIGS. 1Aand 1B, except for the conductive lines formed onto the TSV structure28. Referring to FIG. 20, two first conductive lines 36 contact firstparts of the outer planar portion of the top surface of the TSVstructure 28. A second conductive line 37 has two pieces extendingparallel between the first conductive lines 36 over the center of theTSV structure 28. Such pieces of the second conductive line 37 contactparts of the outer planar portion of the top surface of the TSVstructure 28 between the first conductive lines 36.

The semiconductor device of FIG. 20 may be formed similarly as in FIGS.2, 3, 4, 5, 6, 7, 8, and 9, except for the position and shape of thefirst openings 34.

FIG. 21 is a cross-sectional view including additional conductivestructures such as upper wirings formed in the semiconductor device ofFIGS. 1A and 1B, according to an example embodiment of the presentinvention. Referring to FIG. 21, the conductive line 36 is formed ontothe outer planar portion of the TSV structure 28 such as illustrated inFIG. 1A, 18A, 18B, 19, or 20.

The first inter-metal dielectric layer 32 surrounds the conductive linestructure 36. The second inter-metal dielectric layer 38 is formed onthe first inter-metal dielectric layer 32 and the conductive linestructure 36. The upper wirings 40 are formed through the secondinter-metal dielectric layer 38 with each upper wiring 40 including anupper conductive line 40 a and an upper contact 40 b. The upper wirings40 are formed to not overlap the protrusion portion 27 of the TSVstructure 28 in FIG. 21.

The portion of the second inter-metal dielectric layer 38 formed overthe protrusion portion 27 of the TSV structure 28 may not be planar.Thus, the upper wirings 40 are formed to not overlap such a protrusionportion 27 such that the upper wirings 40 are formed to be planar. Thesemiconductor device of FIG. 21 is formed similarly as in FIGS. 2, 3, 4,5, 6, 7, 8, and 9, except for the positions of the upper wirings 40.

FIGS. 22 and 23 are cross-sectional and top views illustrating asemiconductor device having a via structure with a center fill,according to an alternative example embodiment of the present invention.Referring to FIGS. 22 and 23, the first circuit pattern 12 is formed onthe first substrate 10 to include transistors, diodes, and the like forforming an integrated circuit.

The first insulating interlayer 14 surrounds the first circuit pattern12 on the first substrate 10. A lower wiring 16 is formed through thefirst insulating interlayer 14 to connect to the first circuit pattern12. A via hole 68 is formed through the first insulating interlayer 14and at least a portion of the first substrate 10. The via hole 68 has atop view of an oval shape according to an example embodiment of thepresent invention.

An insulation layer pattern 70 a is formed on an inner wall of the viahole 68, and a barrier layer pattern 72 a is formed on the insulationlayer pattern 70 a. The barrier layer pattern 72 a is comprised of ametal or a metal nitride such as tantalum, tantalum nitride, titanium,titanium nitride, ruthenium, cobalt, nickel, nickel boride, tungstennitride, and the like, alone or in a combination thereof.

A conductive fill 74 a is formed to fill the via hole 68 with thebarrier layer pattern 72 a surrounding the conductive fill 74 a. Theconductive fill 74 a has a cup shape surrounding a center fill 78 a. Theconductive fill 74 a is comprised of a metal having a low resistance anda thermal expansion coefficient of about 2 times of that of silicon suchas copper, aluminum, gold, indium, nickel, and the like, alone or in acombination thereof. In an example embodiment of the present invention,the conductive fill 74 a is comprised of copper. The conductive fill 74a and the barrier layer pattern 72 a define a TSV structure 76.

The center fill 78 a is formed in a center of the via hole 68 and iscomprised of an insulating material or a conductive material accordingto an example embodiment of the present invention. For example, thecenter fill 78 a is comprised of spin on glass (SOG), flowable oxide(FOX), titanium, aluminum, a porous material, and the like.

In any case, the material of the center fill 78 a has a thermalexpansion coefficient that is from about three times to about four timeslower than a thermal expansion coefficient of the material of theconductive fill 74 a. For example, the conductive fill 74 a comprised ofcopper has a thermal expansion coefficient of 17 PPM (parts permillion)/° C. In that case, the center fill 78 a is comprised of amaterial having a lower thermal expansion coefficient of from about 3PPM (parts per million)/° C. to about 4 PPM (parts per million)/° C.

In FIGS. 22 and 23, the conductive fill 74 a includes a protrusionportion 75 having a ring shape along a center portion of the top surfaceof the cup-shaped conductive fill 74 a. An outer portion of the topsurface of the conductive fill 74 a disposed near the center fill 78 aand the insulation pattern 70 a is planar with the top surface of thefirst insulating interlayer 14.

The buffer layer 30 is formed on the TSV structure 76 and the firstinsulating interlayer 14. A plurality of conductive lines 80 a areformed to contact the outer planar portion of the top surface of the TSVstructure 76 and to contact the lower wiring 16 through the firstinter-metal dielectric layer 32 and the buffer layer 30. The conductivelines 80 a are not formed onto and do not contact the protrusion portion75.

In an example embodiment of FIG. 23, two parallel conductive lines 80 acontact outer planar portions of the top surface of the TSV structure76. Alternatively, more than two conductive lines 80 a may be formed tocontact planar portions of the top surface of the TSV structure 76. Inany case, the conductive lines 80 a are formed to contact from about 5%to about 80% of the entire top surface of the TSV structure 76.

The conductive lines 80 a may be comprised of a barrier layer (notshown) and a conductive material such as a metal having a lowresistance. In an example embodiment of the present invention, theconductive lines 80 a are comprised of copper.

A second inter-metal dielectric layer 38 is formed on the firstinter-metal dielectric layer 32. Upper wirings 40 are formed through thesecond inter-metal dielectric layer 38 to electrically connect to theconductive lines 80 a. Thus, such upper wirings 40 form a linkingstructure for electrically connecting the conductive lines 80 a.Additional insulating inter-layers (not shown) and wirings (not shown)may be further formed after FIG. 22.

FIGS. 24 and 25 are cross-sectional views illustrating steps duringfabrication of the semiconductor device of FIGS. 22 and 23, according toan example embodiment of the present invention. Process steps similar toFIGS. 2 and 3 are first performed to form the first insulatinginterlayer 14 on the first substrate 10. In addition, the via hole 68 isformed through the first insulating interlayer 14 and at least a portionof the first substrate 10.

The via hole 68 may have a top view of a circle or an oval shape.Furthermore, an insulation layer 70 is formed on an inner wall of thevia hole 68 and an etch stop layer 18 formed on the first insulatinginterlayer 14 and the lower wirings 16.

Also in FIG. 24, a barrier layer 72 is formed on the insulation layer70, and a conductive layer 74 is formed on the barrier layer 72. Theconductive layer 74 is comprised of a metal having a low resistance anda thermal expansion coefficient of about 2 times that of silicon. Forexample, the conductive layer 74 is comprised of copper, aluminum, gold,indium, nickel, and the like, alone or in a combination thereof. In anexample embodiment of the present invention, the conductive layer 74 iscomprised of copper.

Further in FIG. 24, a center fill layer 78 is formed on the conductivelayer 74 for filling the remaining portion of the via hole 68. Thecenter fill layer 78 is comprised of SOG, FOX, titanium, aluminum, aporous material, and the like. In an example embodiment of the presentinvention, the conductive layer 74 is comprised of copper having athermal expansion coefficient of 17 PPM (parts per million)/° C. In thatcase, the center fill layer 78 is comprised of a material having a lowerthermal expansion coefficient of from about 3 PPM (parts per million)/°C. to about 4 PPM (parts per million)/° C. Thus, the center fill layer78 buffers the thermal expansion of the conductive layer 74 forminimized height of the protrusion portion 75 that is formed in a ringshape.

Subsequently in FIG. 25, upper portions of the center fill layer 78, theconductive layer 74, the barrier layer 72, the insulation layer 70, andthe etch stop layer 18 are planarized until a top surface of the firstinsulating interlayer 14 is exposed. In this manner, the TSV structure76 is formed to be contained in the via hole 68. The process steps ofFIGS. 6, 7, 8, and 9 may then be performed after FIG. 25 to complete thesemiconductor device of FIG. 22.

FIGS. 26, 27, and 28 are top views of a semiconductor device havingmultiple conductive structures formed onto multiple via structures,according to example embodiments of the present invention. Thesemiconductor device of FIG. 26 is similar to the semiconductor deviceof FIG. 19, except for TSV structures 76 a and 76 b formed in a cupshape to surround the center fills 78 a and 78 b, respectively,similarly as described in reference to FIG. 25.

Referring to FIG. 26, a conductive line 81 is divided into multiplepieces that extend along a plurality of the TSV structures 76 a and 76b. Each of the TSV structures 76 a and 76 b is formed similarly asdescribed in reference to FIG. 25. Each of the pieces of the conductiveline 81 contacts the outer planar portion of at least one of the TSVstructures 76 a and 76 b. Such pieces of the conductive line 81 areelectrically connected by the TSV structures 76 a and 76 b.

In the example embodiment of FIG. 26, the conductive line 81 is dividedinto three pieces. One piece of the conductive line 81 contacts portionsof the outer planar surface of the top surfaces of the first and secondTSV structures 76 a and 76 b. Another piece of the conductive line 81contacts a portion of the outer planar surface of the top surface of thefirst TSV structure 76 a. The other piece of the conductive line 81contacts a portion of the outer planar surface of the top surface of thesecond TSV structure 76 b.

The first TSV structure 76 a includes a first conductive fill 74 a and afirst barrier layer pattern 72 a. The second TSV structure 76 b includesa second conductive fill 74 b and a second barrier layer pattern 72 b.Each of the first and second conductive fills 74 a and 74 b has arespective center protrusion portion 27 in the shape of a ring.

The first center fill 78 a is surrounded by the first conductive fill 74a, and the second center fill 78 b is surrounded by the secondconductive fill 74 b. The semiconductor device of FIG. 26 may bemanufactured by process steps similar to FIGS. 24 and 25, except for theposition and shape of the conductive line structure 81.

FIG. 27 is a top view of a semiconductor device according to anotherexample embodiment of the present invention. For convenience ofillustration and description, only TSV structures and conductive linesare shown in FIG. 27. However, additional structures similar to FIG. 22may also be formed for the semiconductor device of FIG. 27.

In FIG. 27, the semiconductor device includes a plurality of TSVstructures 90 a, 90 b, and 90 c, each being formed similar to the TSVstructure 76 of FIG. 22. The three TSV structures 90 a, 90 b, and 90 ctogether form a larger TSV structure 92. For example, when a TSVstructure having a larger diameter is desired, forming such a larger TSVstructure with a large diameter may be difficult and result in aprotrusion region with undesired height. Thus, the plurality of TSVstructures 90 a, 90 b, and 90 c are formed with relatively smallerdiameter to together form the larger TSV structure 92. Each of the TSVstructures 90 a, 90 b, and 90 c with relatively smaller diameter hasminimized height of the protrusion portion.

Each of the TSV structures 90 a, 90 b, and 90 c surrounds a respectivecenter fill 94 and includes a respective protrusion region 95 having aring shape. Each of a plurality of conductive line structures 96 isformed onto and contacts the outer planar portions of the top surfacesof a respective set of at least two of the TSV structures 90 a, 90 b,and 90 c. Each of the conductive line structures 96 does not contact theprotrusion region 95 of the TSV structures 90 a, 90 b, and 90 c.

The conductive lines 96 extend parallel with each other and are dividedinto multiple pieces as illustrated in FIG. 27. Such pieces of theconductive lines 96 are electrically connected to each other by the TSVstructure 92. The conductive lines 96 are formed onto and contact fromabout 5% to about 80% of the entire top surfaces of the TSV structures90 a, 90 b, and 90 c.

FIG. 28 is a top view of a semiconductor device according to anotherexample embodiment of the present invention. For convenience ofillustration and description, only TSV structures and conductive linesare shown in FIG. 28. However, additional structures similar to FIG. 22may also be formed for the semiconductor device of FIG. 28.Additionally, the semiconductor device of FIG. 28 is similar to FIG. 27,except for the shape of the TSV structure 93.

The semiconductor device in FIG. 28 includes a plurality of TSVstructures 91 a, 91 b, and 91 c, each being formed similar to the TSVstructure 28 of FIGS. 1A and 1B. The three smaller TSV structures 91 a,91 b, and 91 c together form a larger TSV structure 93. Each of the TSVstructures 91 a, 91 b, and 91 c include a respective center protrusionportion 97.

Further referring to FIG. 28, a plurality of conductive line structures96 are formed onto and contact parts of the outer planar portions of aset of at least two of the TSV structures 91 a, 91 b, and 91 c. Theconductive lines 96 do not contact the protrusion portions 97 of the TSVstructures 91 a, 91 b, and 91 c. The conductive lines 96 are formed toextend along lines between the TSV structures 91 a, 91 b, and 91 c andare parallel to each other.

The conductive lines 96 are divided into multiple pieces, and each pieceis formed onto and contacts parts of the outer planar portions of a setof at least two of the TSV structures 91 a, 91 b, and 91 c. Such piecesof the conductive lines 96 are electrically connected to each other bythe TSV structure 93. The conductive lines 96 are formed onto andcontact from about 5% to about 80% of the entire top surfaces of the TSVstructures 91 a, 91 b, and 91 c. In the semiconductor device of FIGS.26, 27, and 28, upper wirings (not shown) may also be formed as alinking structure for connecting together the conductive line pieces 81or 96.

FIG. 29 is a block diagram of a system having a stacked semiconductordevice such as shown in FIG. 12 for example according to an exampleembodiment of the present invention. Referring to FIG. 29, the systemincludes a controller 520 and a memory 510. The memory 510 is a DRAMdevice or a flash memory device being implemented as the stackedsemiconductor device such as shown in FIG. 12 for example. The memorycontroller 520 provides an input signal for controlling operation of thememory 510.

FIG. 30 is a block diagram illustrating a system having a stackedsemiconductor device such as shown in FIG. 12 for example according toanother example embodiment of the present invention. Referring to FIG.30, the system includes a host 700 and a memory 510. The memory 510 is aDRAM device or a flash memory device being implemented as the stackedsemiconductor device such as shown in FIG. 12 for example.

The host 700 may be included in a desktop computer, a laptop computer, acamera, a mobile device, a communication device, and the like. The host700 provides an input signal for controlling and operating the memory510. The memory 510 may serve as a data storing media.

FIG. 31 is a block diagram of a system 600 having a stackedsemiconductor device such as shown in FIG. 12 for example according toanother example embodiment of the present invention. Referring to FIG.31, the system 600 may be a portable device that includes a memory 510implemented as the stacked semiconductor device such as shown in FIG. 12for example. Examples of the portable device 600 include an MP3 player,a video player, a portable multi-media player (PMP), etc.

The portable device 600 includes the memory 510, a memory controller520, an encoder/decoder (EDC) 610, a display element 620, and aninterface 670. Data is input to or output from the memory 510 by way ofthe memory controller 520. As illustrated with the dashed lines of FIG.31, data may be directly input from the EDC 610 to the memory 510, ordata may be directly output from the memory 510 to the EDC 610.

The EDC 610 encodes data to be stored in the memory 510 such as byencoding audio and/or video data stored in the memory 510 of an MP3player or a PMP player. Further, the EDC 610 may perform MPEG encodingfor storing video data in the memory 510. Moreover, the EDC 610 mayinclude multiple encoders to encode different types of data depending ontheir formats. For example, the EDC 610 may include an MP3 encoder forencoding audio data and an MPEG encoder for encoding video data.

The EDC 610 may also decode data that is output from the memory 510 suchas by performing MP3 decoding for audio data from the memory 510.Alternatively, the EDC 610 may perform MPEG decoding of video data fromthe memory 510. Moreover, the EDC 610 may include multiple decoders todecode different types of data depending on their formats. For example,the EDC 610 may include an MP3 decoder for audio data and an MPEGdecoder for video data.

In other embodiments, the EDC 610 may include only a decoder. Forexample, encoded data may be input to the EDC 610, and then the EDC 610may decode the input data for transfer in the memory controller 520 orthe memory 510.

The EDC 610 may receive data to be encoded or data being encoded by wayof the interface 670. The interface 670 complies with establishedinterface standards (e.g., FireWire, USB, etc.) to include a FireWireinterface, a USB interface, etc. Thus, data may be output from thememory 510 by way of the interface 670.

The display element 620 displays a representation of user data that isoutput from the memory 510 and decoded by the EDC 610. Examples of thedisplay element 620 include a speaker outputting an audio representationof the data, a display screen outputting a video representation of thedata, etc.

The foregoing is illustrative of example embodiments and is not to beconstrued as limiting thereof. Although a few example embodiments havebeen described, those skilled in the art will readily appreciate thatmany modifications are possible in the example embodiments withoutmaterially departing from the novel teachings and advantages of thepresent inventive concept.

Accordingly, all such modifications are intended to be included withinthe scope of the present inventive concept as defined in the claims. Inthe claims, means-plus-function clauses are intended to cover thestructures described herein as performing the recited function and notonly structural equivalents but also equivalent structures.

Therefore, it is to be understood that the foregoing is illustrative ofvarious example embodiments and is not to be construed as limited to thespecific example embodiments disclosed, and that modifications to thedisclosed example embodiments, as well as other example embodiments, areintended to be included within the scope of the appended claims.

The present invention is limited only as defined in the following claimsand equivalents thereof.

The invention claimed is:
 1. A semiconductor device, comprising: a viastructure having an upper surface with a planar portion and with arounded protrusion portion, the rounded protrusion portion beingsurrounded by the planar portion; and a conductive line disposed atleast on the planar portion of the upper surface of the via structure,wherein the conductive line is not disposed over at least a part of saidrounded protrusion portion of the upper surface of the via structure,and wherein the via structure is a TSV (through silicon via) formedwithin an opening through a semiconductor substrate and through adielectric layer formed over the semiconductor substrate.
 2. Thesemiconductor device of claim 1, wherein another conductive line extendsover a central portion of the upper surface of the via structure.
 3. Asemiconductor device, comprising: a via structure having an uppersurface with a planar portion and with a rounded protrusion portion, therounded protrusion portion being surrounded by the planar portion; and aplurality of conductive structures on the upper surface of the viastructure, wherein at least one of the plurality of conductivestructures is formed on the planar portion of the upper surface of thevia structure while not being disposed over at least a part of saidrounded protrusion portion of the upper surface of the via structure,and wherein the via structure is a TSV (through silicon via) formedwithin an opening through a semiconductor substrate and through adielectric layer formed over the semiconductor substrate.
 4. Thesemiconductor device of claim 3, wherein at least one of the pluralityof conductive structures is formed on a central portion of the uppersurface of the via structure.
 5. The semiconductor device of claim 3,wherein at least one of the plurality of conductive structures is formedboth on the upper surface of TSV and an upper surface of the dielectriclayer that is adjacent to the upper surface of TSV.
 6. The semiconductordevice of claim 3, wherein each of the plurality of conductivestructures extends in a first direction and the plurality of conductivestructures are spaced apart from each other in a second directionsubstantially perpendicular to the first direction, and wherein at leastone of the plurality of conductive structures contacts both of the uppersurface of TSV and an upper surface of the dielectric layer that isadjacent to the upper surface of the TSV along the second direction. 7.The semiconductor device of claim 3, wherein the TSV includes: aninsulation layer disposed at an inner wall of the opening; a barrierlayer disposed on the insulation layer within the opening; and aconductive fill within the opening with the barrier layer surrounding atleast a portion of the conductive fill.
 8. The semiconductor device ofclaim 7, wherein the TSV further includes: a center fill within theopening with the conductive fill surrounding at least a portion of thecenter fill.
 9. The semiconductor device of claim 8, wherein the centerfill has a thermal expansion coefficient that is lower than that of theconductive fill such that the rounded protrusion portion is formed as aring.
 10. The semiconductor device of claim 3, wherein the TSV iscoupled to a contact structure of another semiconductor device forforming a stacked semiconductor device.
 11. The semiconductor device ofclaim 10, wherein the stacked semiconductor device is a memory device.12. The semiconductor device of claim 3, further comprising a bufferlayer on a portion of the upper surface of the via structure that is notcovered by the plurality of conductive structures.
 13. A semiconductordevice, comprising: a via structure filling an opening through asemiconductor substrate, the via structure having an upper surface witha planar portion and with a protrusion portion, the planar portionsurrounding and directly contacting the protrusion portion, and both ofthe planar portion and the protrusion portion vertically overlapping theopening, wherein the planar portion and the protrusion portion arecomprised of a same conductive material; and a conductive line formed todirectly contact at least a part of the planar portion of the uppersurface of the via structure, and wherein the conductive line does notdirectly contact at least a part of said protrusion portion of the uppersurface of the via structure; and wherein an uppermost level of theprotrusion portion is disposed further from the semiconductor substratethan any of the planar portion.
 14. The semiconductor device of claim13, wherein the via structure is a TSV (through silicon via) filling theopening through the semiconductor substrate and penetrating through adielectric layer formed over the semiconductor substrate.
 15. Thesemiconductor device of claim 13, wherein the TSV includes: aninsulation layer disposed on an inner wall of the opening; a barrierlayer disposed on the insulation layer within the opening; and aconductive fill within the opening with the barrier layer surrounding atleast a portion of the conductive fill.